Distribution systems.
Most households have more than one television.
A distribution system is a neat solution to supplying a good clean signal to each room with just one Aerial,rather than an hotchpotch system that grew over several years,giving lousy results all over the house,with two or more rickety Aerials hanging off the chimney pot,like below!

The amplifier sits in the loft, tucked away,mains powered.
Sky can also be distributed around the house,along with signals from security cameras allowing you to see the image on any television that you are watching at the time.
You will need a mains point in your loft,if you don't have one our electrician can fit you one.
Cost is from £50 to £100, depending on how difficult it is to route the cable.